Image from Canvas

[manu g]

i have drawn an image in canvas,now i want to make it as an image so that i be able to extract the pixel information from it,how can i make an Image object from the information in canvas

[Thomas Paul]

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Thanks.

[Nathan Pruett]

Manu,
The way I would do it is use the createImage( x, y ) method in Component to create a "back buffer" image ( normally used in double buffering ) that you do all the drawing to in your paint method. Then, at the end of the paint method, you simply do a g.drawImage( buffer, 0, 0, this ) to draw to the screen. You would also have a reference to the image being shown on the screen.

public class BufferImage extends Frame
{
    private Image buffer;  // the image
    private Graphics bg;   // the graphics context of buffer
    private Canvas c;      // a canvas
    private int x, y;      // the size of the canvas and buffer
     
    BufferImage()
    {
        c = new Canvas();
        x = 100;
        y = 100;
        c.setSize( x, y );
        add( c );
    }
     
    public void paint( Graphics g )
    {
        if( buffer == null )
        // Initialize here to keep from getting NullPointerExceptions...
        {
            buffer = c.createImage( x, y );
            bg = buffer.getGraphics();
        }
        
        // Clear the screen...
        bg.setColor( getBackground() );
        bg.fillRect( 0, 0, x, y );
         
        // Draw things to buffer....
        bg.drawOval();
        bg.fillRect();
        bg.drawImage();
         
        // Draw buffer to screen
        g.drawImage( buffer, 0, 0, this );
    }
}

HTH,
-Nate
[This message has been edited by Nathan Pruett (edited April 12, 2001).]